A set of state based CRDTs implemented in Erlang and on the paper - A Comprehensive study of Convergent and Commutative Replicated Data Types - which you may find an interesting read.
What happend to riak_dt, the database?
Riak is getting CRDT support built in, so we've archived the old
riak_dt in the branch
prototype. No further work will be done on
it. This repo is now a resuable library of Quickcheck tested
implementations of CRDTs.